To create a private encrypted folder in ubuntu is very easy by ecryptfs. eCryptfs is a cryptographic stacked Linux filesystem. eCryptfs stores cryptographic metadata in the header of each file written, so that encrypted files can be copied between hosts; the file will be decrypted with the proper key in the Linux kernel keyring. There is no need to keep track of any additional information aside from what is already in the encrypted file itself. You may think of eCryptfs as a sort of “gnupgfs”, or “gnupg as a filesystem”.

eCryptfs is widely used, as the basis for Ubuntu’s Encrypted Home Directory, natively within Google’s ChromeOS, and transparently embedded in several network attached storage (NAS) devices.